1. Field of the Invention
The present invention relates to a television system, and more particularly, to a method of displaying a channel indicator on a TV screen using an On-Screen-Display (OSD) function.
2. Discussion of the Related Art
Reference will now be made to an existing method of displaying a present-channel indicator on a TV screen using an On-Screen-Display (OSD) function, examples of which are illustrated in FIG. 1 and FIG. 2. A typical television system (not illustrated) generally includes a display unit; a microcomputer that generates a control signal for switching to a desired channel and displaying the channel number of the newly selected channel for a predetermined period of time on a predetermined region of a TV screen, upon receiving an input command for switching to the desired channel from a user; a tuner that tunes to the desired channel according to the control signal; and an image output unit performing required functions on an image signal of the tuned channel for enabling the display unit to display the image signal and the channel number of the desired channel.
When a user inputs a channel-switching command into a television system, the microcomputer initially stores the channel information of the desired channel selected by the user. Upon receiving a control signal from the microcomputer, the tuner tunes to the desired channel. Then the image output unit performs the required processes on an image signal of the tuned channel so that the display unit is able to display the image signal. The image output unit enables the display unit to display the channel number of the tuned channel for a predetermined period of time on a designated region on the TV screen by combining a channel OSD signal with the image signal of the tuned channel upon receiving a control signal from the microcomputer. The channel number displayed on the TV screen disappears after the predetermined period of time, and these processes of displaying the channel number of a desired channel are repeated when the user inputs another channel-switching command into the television system.
FIG. 1 is a flow chart illustrating the steps of the existing method of displaying a present-channel number on a TV screen using an OSD function. Referring to FIG. 1, the television system initially checks whether the user has inputted a channel-up command by pressing a channel-up button (S1). If the user has, then it tunes to a channel ordered right above the present channel and displays its corresponding channel number for the predetermined period of time on the designated region of the TV screen (S3) as shown in FIG. 2. Otherwise, the television system further checks whether the user has inputted a channel-down command by pressing a channel-down button (S4). If it is found that the user has inputted the channel-down command, then the television system tunes to a channel ordered right below the present channel and displays its corresponding channel number for the predetermined period of time on the designated region of the TV screen (S3).
Since the existing television system displays the channel number of the selected channel only, the user may not know which channels are sequenced adjacent to the presently selected channel before actually switching to one of such adjacent channels. In addition, there are only a limited number of channel-switching keys provided on a remotely control device: channel-up and channel down button keys. For this reason, it often takes long time for a user to switch to a desired channel with such remotely control device, and this may give a great inconvenience to the user.